Remember the good old days when your beer came in bottles that you returned so they could be reused?  Not just beer, but also soda was sold in such bottles, and you knew they were because they bore the marks of many trips through the washing process--marks left on the outside of the bottles by the rollers used to push them through the washer.  The family-owned Straub Breweries of St. Mary's, Pennsylvania, is now asking people to find any of their bottles that are out there and return them to the company.  Straub officials say there are many thousands of their bottles out there, most likely collecting dust in people's garages and basements,  The company says if those bottles are returned, they will be able to continue selling beer in returnable bottles, but if they aren't, then Straub will stop selling them be year's end.  After this summer, they will be the only brewery selling beer in returnable bottles, but if they don't get their old bottles back, they'll be forced to concentrate on cans and throw-away bottles.